During the production of textile fiber products, including carpeting, dye can be applied to the textile in order to produce a certain color. When changes or “shifts” in color occur, such as when a new color or colors are to be applied to a production run of carpet, it can be informative to know when the color shift has occurred. Typically, color shifts occur when the dye or dyes used to produce the old color or colors have been fully expended and the new dye or dyes used to produce the new color or colors have become introduced into the production process. A complete color shift is said to have occurred when the new color or colors are produced in a manner of predetermined uniformity. It can be informative to know where on the run of carpet that this shift has occurred so that a long run of carpet can be separated into sections of uniform color. In addition, waste can be reduced and non-uniform product can be removed.